JP2007278622A - Flat burner and combustion apparatus using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide stable supply in just proportion of secondary air, in a flat burner provided with flame hole parts 11, 12 of an upper end and mixing pipe parts 13, 15 connected to the flame hole parts in a burner body 10 that is longitudinal in a fore and aft direction and arranged such that a front end faces a primary air supply chamber in a combustion casing, and formed with inflow ports 13a, 15a of upstream ends of the mixing pipe parts, in the front end of the burner body such that they are communicated with the primary air supply chamber. <P>SOLUTION: A secondary air cover 103 partitioning off the burner body from a secondary air passage having an outflow port 17b positioning in a horizontal outer side of a flame hole part 12, is provided in an outer side part of at least one horizontal side of the burner body 10. In an outer side part of the front end of the burner body 10, an inflow port 17a of an upstream end of the secondary air passage is formed such that it is communicated with the primary air supply chamber. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a flat burner in which a burner body which is long in the front-rear direction is provided with a flame port at the upper end and a mixing tube portion connected to the flame port, and a combustion apparatus in which a plurality of flat burners are arranged side by side in a combustion housing. About.

  Conventionally, in a combustion apparatus in which a plurality of flat burners are arranged side by side in a combustion housing, an air inflow chamber partitioned by a partition plate is defined at the lower portion of the combustion housing with a partition plate, Air sent from the fan to the air inflow chamber is supplied as secondary air for combustion to the burner arrangement portion through a number of distribution holes formed in the partition plate (see, for example, Patent Document 1). A primary air supply chamber rising from the front part of the air inflow chamber is provided in the combustion housing, and the front end part of the burner body of the flat burner faces the primary air supply chamber. An inflow port at the upstream end of the mixing tube portion is formed at the front end portion of the burner body so as to communicate with the primary air supply chamber, and a gas nozzle faces the inflow port of the mixing tube portion. Therefore, primary air flows into the mixing tube portion from the primary air supply chamber, and fuel gas from the gas nozzle flows into the mixing tube portion, so that an air-fuel mixture is generated in the mixing tube portion. Then, the air-fuel mixture is ejected from the flame port at the upper end of the burner body, and the air-fuel mixture is combusted by receiving secondary air supplied from the air inflow chamber through the gap between the distribution hole and the flat burner.

By the way, the air inflow chamber is a portion that directly receives the dynamic pressure from the air supply fan, and the pressure distribution becomes non-uniform. Even if the arrangement of the distribution holes of the partition plate is devised, the air inflow chamber flows into the individual flat burners. There will be some variation in the amount of secondary air. In addition, it is difficult to assemble the combustion apparatus so that all the gaps between the flat burners are uniform, and the amount of secondary air flowing through the individual flat burners varies even if the gaps are wide or narrow. In addition, since it is necessary to control the air flow rate of the air supply fan so that the necessary and sufficient secondary air is supplied to the flat burner where the secondary air does not easily flow, the flat burner where the secondary air is easy to flow is used. The secondary air will be supplied excessively. Here, if the secondary air is supplied excessively, the excessive secondary air reaches the object to be heated without contributing to the combustion, cools it, and the thermal efficiency decreases. Therefore, the conventional combustion apparatus has a limit in improving the thermal efficiency.
JP-A-7-190497

  In view of the above, it is a first object of the present invention to provide a flat burner capable of stably supplying secondary air without excess or deficiency, and using the flat burner as much as possible in thermal efficiency. It is a second object to provide a combustion apparatus that can be improved.

  In the present invention, a burner body that is long in the front-rear direction and disposed so that the front end faces the primary air supply chamber in the combustion housing is provided with a flame port at the upper end and a mixing tube unit that is continuous with the flame port. In the flat burner formed so that the inlet of the upstream end of the mixing tube portion communicates with the primary air supply chamber at the front end portion, in order to solve the first problem, the outer side of at least one side in the lateral direction of the burner body Is provided with a secondary air cover that defines a secondary air passage having an outlet located laterally outside the flame opening portion between the burner body and the outer side of the front end portion of the burner body. The inlet of the upstream end of the secondary air passage is formed so as to communicate with the primary air supply chamber.

  Further, according to the present invention, a flat burner in which a burner main body elongated in the front-rear direction is provided with a flame port at the upper end and a mixing tube portion connected to the flame port, the front end of the burner main body is disposed in the combustion housing. A plurality of combustion devices arranged side by side in a state of facing the primary air supply chamber, wherein the inlet of the upstream end of the mixing tube portion is connected to the front end portion of the burner body of each flat burner. In order to solve the second problem, each of the flat burners is provided with a secondary air cover only on the outer side on one side in the lateral direction of the burner body. Or a flat burner arranged every other flat burner, wherein the secondary air covers are provided on the outer sides of both sides of the burner body in the lateral direction. It is composed of a burner.

  In the flat burner of the present invention, the air in the primary air supply chamber in the combustion housing is supplied as secondary air to the outer side of the flame opening at the upper end of the burner body via the secondary air passage. Here, since the primary air supply chamber needs to stabilize the amount of primary air flowing into the mixing pipe portion of each flat burner and supply the air-fuel mixture having a required air-fuel ratio to the flame port, The distribution is formed to be almost uniform. Therefore, the amount of secondary air flowing into the secondary air passage from the primary air supply chamber does not vary between the individual flat burners. Further, since the secondary air passage is defined by a secondary air cover provided on the outer side of the burner body, it can be easily manufactured and managed so that the width of the secondary air passage does not differ between the individual flat burners. Therefore, it is possible to prevent the secondary air amount from being varied by the individual flat burners due to the difference in the width of the secondary air passage. Therefore, the secondary air can be stably supplied without excess or deficiency.

  In a combustion apparatus in which a plurality of flat burners are arranged side by side in the combustion housing, if the flat burner of the present invention is used, good combustion can be achieved in all the flat burners even if the amount of supplied air is minimized. Done. Therefore, thermal efficiency is improved as much as possible without causing a decrease in thermal efficiency due to excessive secondary air.

  In the above combustion apparatus, each flat burner can be constituted by the flat burner of the present invention in which the secondary air covers are provided on the outer side portions on both sides in the lateral direction of the burner body. The arrangement pitch becomes wider, and the combustion apparatus becomes larger. Here, the air ejected from the outlet of the secondary air passage can be shared as the secondary air of the two flat burners on both sides thereof. Therefore, it is only necessary to provide one secondary air passage between adjacent flat burners. And like the combustion apparatus of the said invention, each flat burner is comprised with the flat burner of this invention in which the secondary air cover was provided only in the outer side part of the horizontal direction one side of a burner main body, or two or more pieces. If the flat burners arranged every other flat burner are composed of the flat burners of the present invention in which the secondary air covers are provided on the outer sides of both sides in the horizontal direction of the burner main body, between adjacent flat burners One secondary air passage is provided for each. According to this, the arrangement | positioning pitch of a flat burner does not become wide, and the enlargement of a combustion apparatus can be avoided.

  Moreover, in the combustion apparatus of this invention, it is desirable to provide the damper facing the inflow port of the secondary air path of the flat burner comprised with the flat burner of this invention in the primary air supply chamber. According to this, even if the pressure distribution in the lateral direction of the primary air supply chamber becomes somewhat uneven, the secondary air supply amount can be set for each flat burner by appropriately setting the size of the damper hole formed in the damper. It can prevent variation.

  In addition, if secondary air spouts from the front-back direction whole area of the outflow port of a secondary air path, the fire transfer between adjacent flat burners will be prevented by a secondary air flow. Therefore, it is desirable that a closing portion that suppresses the ejection of secondary air is provided at the outlet of the secondary air passage at a predetermined position in the front-rear direction of the outlet. According to this, the fire is transferred without being obstructed by the secondary air flow immediately above the closed portion, and the fire transfer property is improved.

  By the way, a flat burner is located at the upper end of the burner main body as a flame mouth portion, a main flame mouth portion that emits a lean air-fuel mixture whose fuel concentration is less than the stoichiometric air-fuel ratio, and both sides of the main flame mouth portion in the lateral direction. A sub-flame port part for injecting a rich air-fuel mixture having a fuel concentration higher than the air-fuel ratio, and a burner body as a mixing pipe part located above the main mixing pipe part and a main mixing pipe part connected to the main flame port part In the case of a so-called concentration combustion burner provided with a submixing tube portion connected to the subflame port portion, a lateral side generated at a portion between the main mixing tube portion and the submixing tube portion on the outer surface of the front end portion of the burner body. It is desirable that the inlet of the secondary air passage is provided so as to match the inwardly recessed portion. According to this, the indentation opening area of a secondary air passage can be taken widely by utilizing effectively the hollow part between a main mixing pipe part and a submixing pipe part, and space efficiency improves. Moreover, although a reason is mentioned later, the width | variety of a secondary air path can be made comparatively narrow and it contributes also to size reduction of a combustion apparatus.

  1 to 3 show a flat burner 1 according to an embodiment of the present invention. The burner body 10 of the flat burner 1 is long in the front-rear direction, and as shown in FIG. 3, the main flame mouth portion 11 that is long in the front-rear direction and the lateral direction of the main flame mouth portion 11 on the upper end surface of the burner body 10. A pair of longitudinal sub-flame ports 12, 12 are formed in the front-rear direction located on both sides. Then, a light mixture whose fuel concentration is leaner than the stoichiometric air-fuel ratio is ejected from the main flame mouth portion 11 and a rich mixture whose fuel concentration is higher than the stoichiometric air-fuel ratio is ejected from each sub-flame mouth portion 12, so-called concentration combustion. I am trying to do.

  In detail, the burner body 10 includes a pair of inner plates 101 and 101 facing each other in the lateral direction, and a pair of outer plates 102 disposed on the laterally outer sides of the upper half portions of the inner plates 101 and 101. 102. Both inner side plates 101, 101 are formed by bending one plate into a palm-joined state at a folding line that becomes the lower edge of the burner body 10, and both outer side plates 102, 102 are a plurality of front and rear edges of the upper edge. The bridge portions 102a are connected to each other. And the main flame opening part 11 is comprised by the clearance gap between the upper end parts of both the inner side boards 101 and 101, and each auxiliary flame opening part 12 is formed by the clearance gap between the upper end parts of each inner side board 101 and each outer side board 102. . In addition, the main flame opening part 11 is equipped with a flow regulating member composed of a plurality of flow straightening plates 11a, and a narrow flame opening channel is defined between the current straightening plates 11a.

  The burner body 10 is formed by pressing the inner plates 101, 101, the main mixing pipe portion 13 located at the lower part of the burner body 10, and the air-fuel mixture from the main mixing pipe portion 13. A passage portion 14 leading to the portion 11 is provided. Here, the passage portion 14 includes a distribution tube portion 14a extending in the front-rear direction on the upper side of the main mixing tube portion 13, and a narrowing portion 14b having a narrow lateral width between the distribution tube portion 14a and the main flame opening portion 11. have. The main mixing pipe portion 13 extends rearward from the inflow port 13a located at the front end portion of the burner body 10, and the rear end portion is bent upward to communicate with the distribution pipe portion 14a.

  The burner body 10 is further provided with a sub-mixing tube portion 15 formed by pressing the inner plates 101 and 101, positioned above the main mixing tube portion 13 and below the distribution tube portion 14a. Yes. The sub-mixing pipe portion 15 terminates slightly backward from the inlet 15a located at the front end portion of the burner body 10, and a plurality of vent holes 15b are formed on the side surface of the rear portion. And between each inner side board 101 and each outer side board 102, the passage part which guides the air-fuel mixture which flows out of the inner side board 101 outside from each sub mixing pipe part 15 via vent hole 15b to each sub flame mouth part 12. 16 is formed. The passage portion 16 is provided with a flow dividing portion 16a composed of a concave portion formed in each outer plate 102 for distributing the flow of the air-fuel mixture from the vent hole 15b in the front-rear direction. In addition, each auxiliary flame opening 12 is divided into a plurality of front and rear blocks by a plurality of front and rear recesses 12a that are formed in the upper end of each outer plate 102 in the vertical direction.

  A pair of secondary air covers 103, 103 are provided on the outer side portions on both sides in the horizontal direction of the burner body 10, and the secondary air covers 103 are provided between the outer surface on each side in the horizontal direction of the burner body 10 and each secondary air cover 103. A secondary air passage 17 is defined. The lower edge of each secondary air cover 103 is joined to the outer surface of the main mixing pipe portion 13. Then, upstream of the secondary air passage 17 so as to coincide with a laterally inwardly recessed portion 10 a generated in a portion between the main mixing tube portion 13 and the sub-mixing tube portion 15 on the outer surface of the front end portion of the burner body 10. An end inflow port 17a is provided.

  The outlet 17 b at the downstream end of the secondary air passage 17 extends in the front-rear direction on the laterally outer side of the auxiliary flame opening 12. The secondary air passage 17 rises rearward along the upper side of the main mixing pipe portion 13 from the inlet 17a to the vicinity of the rear end of the main mixing pipe portion 13, and rises upward. It spreads in the front-rear direction and reaches the outlet 17b. Further, in the secondary air passage 17, a flow dividing portion 17c constituted by a concave portion formed in the secondary air cover 103 that distributes air flowing upward and backward from the vicinity of the rear end of the main mixing pipe portion 13 and an outlet 17b. And a rectifying portion 17d formed of a plurality of longitudinally recessed portions longitudinally formed in the secondary air cover 103, which rectifies the air flow in the vertical direction at the lower position. Moreover, the obstruction | occlusion part 17e which suppresses ejection of secondary air is provided in the front-back direction predetermined location of the outflow port 17b, for example, the center part in the front-back direction. In the present embodiment, the closing portion 17e is brought into contact with the convex portion 17e-1 projecting outward formed on the outer plate 102 and the concave portion 17e-2 recessed inside formed on the secondary air cover 103. It consists of.

  Next, a combustion apparatus according to an embodiment of the present invention configured using the flat burner 1 will be described with reference to FIGS. 4 and 5. This combustion apparatus is for hot water supply, and includes a combustion housing 2 and a heat exchanger 3 disposed above the combustion housing 2 as shown in FIG. In the combustion housing 2, as shown in FIG. 5, the above-described flat burner 1 provided with the secondary air covers 103, 103 on both lateral sides of the burner body 10, and a normal flat burner 1 not provided with the secondary air cover 103. ′ And are alternately arranged in the horizontal direction. The normal flat burner 1 ′ has the same structure as the flat burner 1 except for the secondary air cover 103, and the same members and parts as those of the flat burner 1 are denoted by the same reference numerals. Yes.

  An air inflow chamber 5 partitioned by a partition plate 4 with respect to the burner arrangement portion is defined in the lower portion of the combustion housing 2, and a blower duct 6 connected to an air supply fan (not shown) is connected to the bottom surface of the air inflow chamber 5. Has been. Note that the total combustion amount of the plurality of flat burners 1 and 1 ′ disposed in the combustion housing 1 is variable according to the hot water supply load, and the air blowing amount from the air supply fan depends on the total combustion amount of the flat burners 1 and 1 ′. Variable.

  Further, a primary air supply chamber 7 rising from the front portion of the air inflow chamber 5 is provided in the combustion housing 1. The flat burners 1, 1 ′ are arranged so that the front end portion of the burner body 10 faces the primary air supply chamber 7. Therefore, the main and sub mixing tube portions 13, 15 opening at the front end portion of the burner body 10 are arranged. The inlets 13 a and 15 a communicate with the primary air supply chamber 7. Further, in the flat burner 1 with the secondary air cover 103, the inlet 17 a of the secondary air passage 17 is provided on the outer side of the front end portion of the burner body 10, so that the inlet 17 a also communicates with the primary air supply chamber 7. To do.

  The front surface of the primary air supply chamber 7 is closed by a gas manifold 8. A main gas nozzle 8 a facing the inlet 13 a of the main mixing pipe portion 13 of each flat burner 1, 1 ′ is connected to the gas manifold 8, and a sub mixing pipe. A secondary gas nozzle 8b facing the inlet 15a of the section 15 is provided. Accordingly, primary air flows from the primary air supply chamber 7 into the mixing pipe portions 13 and 15 and combustion gas from the gas nozzles 8a and 8b flows into the mixing pipe portions 13 and 15, and the primary air and fuel gas are mixed in the mixing pipe portions 13 and 15. Mixing produces an air-fuel mixture. And the inflow port 13a of the main mixing pipe part 13 is comparatively large, Therefore, inflow amount of primary air increases in the main mixing pipe part 13, and a light mixture is produced | generated. On the other hand, the inflow port 15a of the submixing pipe portion 15 is relatively small. Therefore, the inflow amount of primary air is reduced in the submixing pipe portion 15 and a rich mixture is generated.

  In addition, air flows into the secondary air passage 17 from the primary air supply chamber 7, and this air is ejected from the outlet 17 b of the secondary air passage 17, and the flat burner 1 located on the lateral side of the outlet 17 b. The secondary flame contributes to the combustion of the rich air-fuel mixture ejected from the secondary flame outlet 12 and the auxiliary flame outlet 12 of the flat burner 1 ′ located on the other side in the lateral direction. Here, unlike the air inflow chamber 5, the primary air supply chamber 7 does not directly receive the dynamic pressure from the air supply fan, and becomes a static pressure region so that the pressure distribution is almost uniform. Accordingly, the amount of secondary air flowing into the secondary air passage 17 does not vary between the individual flat burners 1. Further, since the secondary air passage 17 is defined by the secondary air cover 103 provided on the outer side of the burner body 10, it is easy to prevent the width of the secondary air passage 1 from being different among the individual flat burners 1. Can manage production. Therefore, it is possible to prevent the secondary air amount from being varied by the individual flat burners 1 due to the width difference of the secondary air passage 17. Therefore, even if the amount of air blown from the air supply fan is made the minimum required according to the total combustion amount of all the flat burners 1, 1 ', the secondary air is stably supplied to each flat burner 1, 1' without excess or deficiency. When supplied, the combustion state of all the flat burners 1 and 1 'becomes good. As a result, it is possible to prevent excessive secondary air from reaching the heat exchanger 3 without contributing to combustion and cooling it, thereby reducing the thermal efficiency.

  Note that the air pressure in the primary air supply chamber 7 is slightly higher in the portion in the lateral direction near the air duct 6. And there is a possibility that the amount of air flowing into the mixing pipe portions 13 and 15 and the secondary air passage 17 is slightly different for each of the flat burners 1 and 1 '. Therefore, in the present embodiment, a damper 9 is disposed in the primary air supply chamber 7 along the front end portion of the flat burners 1 and 1 ′, and the damper 9 has the main and sub mixing pipe portions 13 and 15 of the flat burners 1 and 1 ′. Damper holes 9a and 9b facing the inlets 13a and 15a are formed, and damper holes 9c facing the inlet 17a of the secondary air passage 17 of the flat burner 1 are formed. Then, by appropriately setting the sizes of the damper holes 9a, 9b, 9c, the amount of air flowing into the mixing pipe portions 13, 15 and the secondary air passage 17 varies for each flat burner 1, 1 '. It is possible to prevent.

  Moreover, if secondary air spouts over the front-back direction whole region of the outflow port 17b of the secondary air channel | path 17, the fire transfer between adjacent flat burners 1 and 1 'will be prevented by the flow of secondary air. On the other hand, in the flat burner 1 of the said embodiment, since the partial obstruction | occlusion part 17e is provided in the outflow port 17b of the secondary air passage 17, the ejection of secondary air is suppressed in the obstruction | occlusion part 17e. Therefore, the fire moves without being obstructed by the flow of the secondary air immediately above the closing portion 17e, and the fire transfer property is improved.

  By the way, only the flat burner 1 ′ without the secondary air cover 103 is arranged side by side with a gap in the horizontal direction, and the secondary air is distributed through the distribution holes formed in the partition plate 4 from the air inflow chamber 5 as in the conventional case. Is introduced into the burner arrangement portion, the secondary air flows from the lower side of the main mixing tube portion 13 of each flat burner 1 'so as to wrap around its outer surface, and the flow of the secondary air is disturbed. . Therefore, in order to allow the secondary air to flow smoothly upward, the arrangement pitch of the flat burners 1 'is widened, and the gap between the main mixing pipe portions 13, 13 of the adjacent flat burners 1', 1 'is widened. It is necessary to secure. As a result, the lateral width of the combustion device becomes large.

  On the other hand, in the flat burner 1 of the said embodiment, the hollow part 10a to the horizontal inward produced in the part between the main mixing pipe part 13 of the outer side surface of the burner main body 10 and the submixing pipe part 15 of the upper part is produced. Since the inflow port 17a of the secondary air passage 17 is provided so as to match the above, the secondary air flows in from the upper side of the main mixing pipe portion 13. Therefore, unlike the case where the secondary air flows from the lower side of the main mixing pipe portion 13, the flow of the secondary air is not disturbed by the main mixing pipe portion 13. Therefore, even if the width of the secondary air passage 17, that is, the interval between the burner body 10 and the secondary air cover 103 is narrow, the secondary air flows smoothly. Moreover, even if this space | interval is narrow, the opening area of the inflow port 17a is securable by utilizing the said hollow part 10a effectively. As a result, the arrangement pitch of the flat burners 1 and 1 'can be made narrower than the conventional one, and the lateral width of the combustion apparatus can be reduced.

  Next, a second embodiment of the combustion apparatus will be described with reference to FIG. In the second embodiment, all the flat burners 1 arranged in parallel in the combustion housing 2 except for the outermost flat burner 1 adjacent to the side wall of the combustion housing 2, only the outer portion on one side in the horizontal direction of the burner body 10. The secondary air cover 103 is provided. The other structure of this flat burner 1 is the same as the flat burner 1 of the said embodiment, and attaches | subjects the same code | symbol as the above to the same member and site | part. Even in this case, air flows into the secondary air passage 17 from the primary air supply chamber 7, and this air is ejected from the outlet 17b of the secondary air passage 17 and is located on the lateral side of the outlet 17b. It contributes as secondary air to the combustion of the rich air-fuel mixture ejected from the auxiliary flame port 12 of the burner 1 and the auxiliary flame port 12 of the flat burner 1 located on the other side in the lateral direction. The outermost flat burner 1 is provided with secondary air covers 103 and 103 on the outer side portions on both sides in the lateral direction of the burner body 10, and the secondary outer side of the auxiliary flame port portion 12 located on the side wall side of the combustion housing 2. The secondary air can be supplied through the air passage 17.

  As mentioned above, although embodiment of this invention was described with reference to drawings, this invention is not limited to this. For example, in the above-described embodiment, the flat burner 1 is provided with a main flame mouth portion 11 for ejecting a light mixture and a sub flame mouth portion 12 for ejecting a rich mixture with the upper end of the burner body 10 as a flame mouth portion. Although the combustion type flat burner is used, the present invention can be similarly applied to a normal Bunsen type flat burner which does not include the auxiliary flame opening 12.

The perspective view which shows the flat burner of embodiment of this invention. The disassembled perspective view of the flat burner of embodiment. FIG. 3 is a cross-sectional view cut along III-III in FIG. 1. The cut side view which shows the combustion apparatus of embodiment of this invention. FIG. 5 is a cross-sectional view taken along line VV in FIG. 4. Sectional drawing corresponding to FIG. 5 of the combustion apparatus of other embodiment of this invention

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Flat burner, 10 ... Burner main body, 10a ... Recessed part, 103 ... Secondary air cover, 11 ... Main flame opening part, 12 ... Secondary flame opening part, 13 ... Main mixing pipe part, 13a ... Inlet, 15 ... Submixing pipe section, 15a ... inlet, 17 ... secondary air passage, 17a ... inlet, 17b ... outlet, 17e ... closed part, 2 ... combustion housing, 7 ... primary air supply chamber, 9 ... damper.

Claims (6)

Arranged so that the front end faces the primary air supply chamber in the combustion housing, the burner body that is long in the front-rear direction is provided with a flame port at the upper end and a mixing tube that continues to the flame port, and mixing is performed at the front end of the burner body. In the flat burner formed so that the inlet at the upstream end of the pipe portion communicates with the primary air supply chamber,
A secondary air cover that defines a secondary air passage having an outlet located at the laterally outer side of the flame opening portion between the burner body and at least one outer side portion in the lateral direction of the burner body is provided. A flat burner characterized in that an inflow port at an upstream end of the secondary air passage is formed on the outer side of the front end portion of the main body so as to communicate with the primary air supply chamber. The flat burner according to claim 1, wherein a main flame mouth portion for injecting a light mixture whose fuel concentration is leaner than a stoichiometric air-fuel ratio as a flame mouth portion at the upper end of the burner body, and a side of the main flame mouth portion. A sub-flame port portion for injecting a rich air-fuel mixture having a fuel concentration higher than the stoichiometric air-fuel ratio located on both sides in the direction, and the main mixing pipe portion connected to the main flame port portion as the mixing pipe portion in the burner body, In what is provided above the mixing pipe part, and a sub-mixing pipe part connected to the sub-flame port part,
The inflow port of the secondary air passage is provided so as to match a laterally inward depression formed in a portion between the main mixing pipe portion and the sub-mixing pipe portion on the outer surface of the front end portion of the burner body. The flat burner according to claim 1. A flat burner is provided in the combustion housing with a burner body that is long in the front-rear direction and provided with a flame port at the top and a mixing tube that is connected to the flame port, and the front end of the burner body serves as the primary air supply chamber in the combustion housing. Combustion devices arranged side by side in a horizontal direction in a state where they face each other, and formed so that the inlet of the upstream end of the mixing tube portion communicates with the primary air supply chamber at the front end portion of the burner body of each flat burner In what has been
3. A combustion apparatus according to claim 1, wherein each flat burner is constituted by the flat burner according to claim 1 or 2, wherein the secondary air cover is provided only on the outer side of one side of the burner body in the lateral direction. A flat burner is provided in the combustion housing with a burner body that is long in the front-rear direction and provided with a flame port at the top and a mixing tube that is connected to the flame port, and the front end of the burner body serves as the primary air supply chamber in the combustion housing. Combustion devices arranged side by side in a horizontal direction in a state where they face each other, and formed so that the inlet of the upstream end of the mixing tube portion communicates with the primary air supply chamber at the front end portion of the burner body of each flat burner In what has been
A flat burner arranged every other one of the plurality of flat burners is constituted by the flat burner according to claim 1 or 2, wherein the secondary air covers are provided on outer side portions on both sides in the lateral direction of the burner body. Combustion device characterized by that.   The damper which opposes the inflow port of the said secondary air passage of the flat burner comprised with the flat burner of Claim 1 or 2 in the said primary air supply chamber is provided. The combustion apparatus as described.   A closing portion that suppresses secondary air ejection at an outlet of the secondary air passage of the flat burner configured by the flat burner according to claim 1 or 2 at a predetermined position in the front-rear direction of the outlet. The combustion apparatus according to claim 3, wherein the combustion apparatus is provided.

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